Multicenter Review Supports TKI Use in Patients With mRCC and Bone Metastases

An analysis of patterns of care and outcomes for patients with metastatic renal cell carcinoma (mRCC) with bone metastases supported the role of TKIs as the standard of care. Investigators presented findings of the multicenter review at the European Society for Medical Oncology Congress 2022.

Data from 1246 patients who began systematic treatment between January 1, 2018, and June 30, 2021, were collected from 15 centers in the United Kingdom. Bone metastases were present in 28% of patients (n = 353) with 62 patients having bone only and 291 having bone and visceral metastases.

Progression-free survival (PFS) outcomes were reported for patients with intermediate and poor risk mRCC who received treatments as follows: cabozantinib (Cabometyx), other TKIs, ipilimumab (Yervoy) plus nivolumab (Opdivo), immunotherapy/TKI, and nivolumab alone.

In patients with intermediate/poor-risk disease with bone-only metastases (n = 51), the median PFS after first-line treatment was 17.1 months with cabozantinib, 14.6 months with other TKI, 4.6 months with ipilimumab plus nivolumab, and 14.7 months with immunotherapy/TKI. Median PFS for patients with bone and visceral metastases (n = 254) after first-line treatment 8.9 months, 5.6 months, 7.1 months, and 8.8 months, respectively.

In the second-line setting, those with bone only metastases the median PFS was not reached with cabozantinib compared with 9.1 months with other TKIs and 2.1 months with nivolumab alone. Patients with bone and visceral metastases who received second-line cabozantinib had a median PFS of 7.1 months. The median PFS with other TKIs was 6.1months and 3.6 months with nivolumab alone.

“PFS in [patients with] intermediate and poor risk mRCC with bone-only metastases favors TKI-based systemic therapy compared with IO/IO treatment,” the study authors wrote in a poster of the data.

The median overall survival (OS) for all patients with bone metastases was 21 months and investigators noted it was significantly longer among patients with favorable-risk disease at 34.4 months compared with 24 months in the intermediate-risk group and and 8.7 months in the poor-risk group (P < .0001). The median OS was also prolonged in patients who underwent nephrectomy prior to treatment vs those who did not at 32.7 months vs 16.4 months (P < .0001) and in those with bone only metastases vs those with bone and visceral metastases at 29.9 months vs. 19.7 months (P < .05). PFS and OS were analyzed via a Kaplan Meier log-rank test.

Patients included in the analysis had a median age of 65 years (range, 27-90) and 73% were men. International Metastatic RCC Database Consortium risk groupings were as follows: favorable (n = 48), intermediate (n = 195), and poor (n = 109). Nearly half of patients (49%) received 1 line of prior systematic therapy, 36% of patients received 2 lines of therapy, and 15% received 3 or more.

Local therapies patients received included resection (n = 25), stereotactic radiotherapy (n = 4), palliative radiotherapy (n = 72), and vertebroplasty (n = 1). Additionally, 20 patients presented with cord compression, 29% of patients had local treatment of bone metastases, and 35% of patients with metastatic spinal cord compression were treated with radiotherapy and 65% underwent surgery. Histology was as follows: 82% clear cell, 4% papillary, 3% other, 2% unclassified, 2% chromophobe, and 7% had no biopsy.

TKIs, which target the vascular endothelial growth factor receptor, when combined with immune checkpoint inhibitors like nivolumab that target tumor or immune cells surface receptors, continue to show promise when treating mRCC. The investigators concluded that TKIs remain a standard of care for patients with bone metastases in mRCC and OS is consistent with the published literature.

Reference

Challapalli A, Ratnayake G, McGrane J, et all. Patterns of care and outcomes of metastatic renal cell carcinoma (mRCC) patients with bone metastases: a UK multicenter review. Poster presented at: 2022 European Society for Medical Oncology; September 9-13, 2022; Paris, France.